Torque transmitting ball joint driver having a rigid fixation mechanism

ABSTRACT

An articulating driver having a ball-in-socket joint. The driver may include a driver tip having a spherical head, a retention cap having a domed surface to mate with the spherical head, an input shaft, a spring disposed in an end of the input shaft and in a recess of the retention cap opposite that of the domed surface, and a housing that receives the input shaft, the spring, the retention cap and the spherical head. The housing may have a tapered end to positionally retain the spherical head therein. In another aspect, the driver may include a driver tip coupled to the input shaft that includes an interface to engage a screw. A bushing may engage the driver tip at one end and receive the screw at the other end to retain the screw within the driver.

BACKGROUND

In procedures such as an anterior lumbar interbody fusion (ALIF),lateral lumbar interbody fusion (XLIF), cervical spine surgery, etc.,when a disc space has been cleared out, a metal, polymer, or bone spaceris typically implanted between the two adjoining vertebrae. After thesespacers or “cages” are inserted, surgeons often use metal screws,plates, and/or rods to further stabilize the spine. To insert thescrews, a driver device having an articulating driver head may be usedto deliver the screws to their spinal column and lock them into place.

In such a driver device, a u-joint may be provided to allow the driverhead to articulate with respect to an input shaft. However, the u-jointmay have a range of angulation that makes it difficult for a user tomaintain an appropriate force on a component (e.g., a screw) beingdriven. Further, in some drivers, a bushing within the driver head thatretains a driver tip may wear out over time, which causes the driver tipto move around, thus making it difficult for the user to drive thecomponent.

SUMMARY

The present disclosure provides an articulating driver and for aball-in-socket joint. The driver may include a driver tip having aspherical head, a retention cap having a domed surface to mate with thespherical head, an input shaft, a spring disposed in an end of the inputshaft and in a recess of the retention cap opposite that of the domedsurface, and a housing that receives the input shaft, the spring, theretention cap and the spherical head. The housing may have a tapered endto positionally retain the spherical head therein. In accordance with anaspect, the spherical head has a plurality of grooves defined in asurface thereof and the housing defines a plurality of holes. Each ofthe holes may receive a pin that passes through the housing and isreceived within a respective groove of the spherical head.

In accordance with some implementations, there is provided aball-in-socket joint that includes an input shaft, a output shaft havinga spherical head, the spherical head having a plurality of groovesdefined therein, a retention cap having a domed surface to mate with thespherical head, a spring disposed in an end of the input shaft and in arecess of the retention cap opposite that of the domed surface, and ahousing that defines a plurality of holes and receives the input shaft,the spring, the retention cap and the spherical head, The housing mayhave a tapered end to positionally retain the spherical head therein.Each of the holes may receive a pin that passes through the housing andis received within a respective groove of the spherical head.

In accordance with some implementations, there is provided aball-in-socket joint that includes a housing that defines a plurality ofholes, where the housing is tapered at one end. The ball-in-socket jointalso may also include an input shaft, a spring disposed in an end of theinput shaft that is disposed within the housing, a retention capdisposed with the house that receives the spring at one end and has adomed surface at the other end thereof, and an output shaft having aspherical head that is disposed within the housing. The ball shaped headmay have defined therein a plurality of grooves within which pinsinserted into the holes or inward protrusions cooperate to transmittorque from the input shaft to the output shaft.

In accordance with some implementations, there is provided a driverhaving an input shaft adapted to transmit torque and a driver tipcoupled to the input shaft. The driver tip may include an interfacedefined at an end thereof adapted to engage a screw. The driver may alsoinclude a bushing that engages the driver tip at one end and thatreceives the screw at the other end. The screw may be received withinthe bushing to engage the interface, and the input shaft is adapted toapply torque to the screw through the interface and to apply torque tothe bushing by the engagement of the bushing with the driver tip.

In accordance with some implementations, there is provided a method ofengaging a screw with a driver having an input shaft, a bushing, and adriver tip. The method may include engaging the bushing with the drivertip; advancing the bushing along a longitudinal axis of the driver tipin a first direction to expose a screw interface; receiving the screw atthe screw interface; and moving the bushing in a second direction alongthe longitudinal axis to couple a head of the screw with the bushing toretain the screw within the driver.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofillustrative embodiments, is better understood when read in conjunctionwith the appended drawings. For the purpose of illustrating theembodiments, there are shown in the drawings example constructions ofthe embodiments; however, the embodiments are not limited to thespecific methods and instrumentalities disclosed. In the drawings:

FIG. 1A illustrates a driver device having an articulating driver head;

FIG. 1B illustrates a sectional view of the driver device along sectionline A-A of FIG. 1A;

FIG. 1C illustrates a ball-in-socket joint of the driver devices of FIG.1A in greater detail;

FIG. 2 illustrates a retention cap of FIGS. 1A-1C;

FIGS. 3A-3B illustrate a spherical head of FIGS. 1A-1C in greaterdetail;

FIG. 3C illustrates a sectional view of the spherical head along sectionline A-A of FIG. 3B;

FIG. 3D illustrates a sectional view of the spherical head along sectionline D-D of FIG. 3A;

FIG. 4A illustrates an articulation housing assembly of FIGS. 1A-1C ingreater detail;

FIG. 4B illustrates a sectional view of the articulation housingassembly along section line B-B of FIG. 4A;

FIG. 4C illustrates a sectional view of the articulation housingassembly along section line A-A of FIG. 4A;

FIGS. 5-8 illustrate an engagement of a screw with a driver device suchas that shown in FIG. 1;

FIGS. 9-12 illustrate an interaction of a stop region of a bushing ofthe driver device and an aiming device to provide disengagement of thescrew from the driver device according to an embodiment;

FIGS. 13-20 illustrate an interaction of a stop region of a bushing ofthe driver device and an aiming device to provide disengagement of thescrew from the driver device in accordance with another embodiment;

FIGS. 21-25 illustrate another embodiment of the driver device of thepresent disclosure;

FIG. 26 illustrates another embodiment of the driver device of thepresent disclosure;

FIGS. 27A-27C illustrate another embodiment of the articulating driverof the present disclosure;

FIGS. 28A-28C illustrate a first spherical head of the embodiment ofFIGS. 27A-27C;

FIGS. 29A-29C illustrate a second spherical head of the embodiment ofFIGS. 27A-27C;

FIGS. 30A-30B illustrate the articulation housing assembly of theembodiment of FIGS. 27A-27C in greater detail; and

FIG. 31 illustrates a perspective view of the embodiment of FIGS.27A-27C.

DETAILED DESCRIPTION

With references to the FIGS., there is illustrated an articulatingdriver 100 and a ball-in-socket joint 102. As will be described herein,the ball-in-socket joint 102 allows a driver tip 126 or other outputshaft to articulate while transmitting input torque from an input shaft104 to the driver tip 126. The input torque turns e.g., a screw or othercomponent being driven by the articulating driver 100. The articulatingdriver 100 may be a jointed awl, screw driver or drill.

As shown in FIGS. 1A-1C, the articulating driver 100 consists of theinput shaft 104 that, at a first end 106, connects to a handle (notshown) and at a second end 108 connects to an articulation housingassembly 110 that forms an outer portion of the ball-in-socket joint102. The input shaft 104 may be any type of shaft capable oftransmitting input torque from the handle or a power tool to which theinput shaft 104 is attached. At the second end 108 of the input shaft104, a cavity 114 is defined that accepts a spring 116 or the cavitywalls are composed of a spring. One end of the spring 116 is receivedwithin the cavity 114, and the other end of the spring 116 is receivedwithin a recess 118 of a retention cap 120, which is shown in greaterdetail in FIG. 2. As will be described later, the spring 116 providespositional retention of the driver tip 126. The retention cap 120transmits force from the spring 116 to a spherical head 124 of thedriver tip 126 that is secured between the retention cap 120 and atapered inner surface 130 of the articulation housing assembly 110. Asshown in FIG. 2, a domed surface 122 may be defined at an end of theretention cap 120 opposite the recess 118 to receive the spherical head124.

As shown in FIG. 1C, the articulation housing assembly 110 receives thesecond end 108 of the input shaft 104, the spring 116, the retention cap120, and the spherical head 124 of the driver tip 126. As shown in FIG.4, the articulation housing assembly 110 defines holes 136 within whichpins 134 a, 134 b and 134 c are pressed. The pins 134 a, 134 b and 134 care received within grooves 128 a, 128 b and 128 c of the spherical head124 (see, FIGS. 3A-3D). Through the cooperation of the pins 134 a, 134 band 134 c and the grooves 128 a, 128 b and 128 c, the spherical head 124transmits torque to an attachment that is received within a bushing 132(see, FIG. 1A). The bushing 132 provides positional retention of theattachment and may be made from Polyether ether ketone (PEEK) or anappropriate plastic or metal.

In accordance with aspects of the present disclosure, the domed surface122 of the retention cap 120 and the tapered inner surface 130 of thearticulation housing assembly 110 may each have a radius that is similarto, and designed to interface with the spherical head 124 head of thedriver tip 126. These radii allow the driver tip 126 to articulatewithin the articulation housing assembly 110, while retaining thespherical head 124 within the articulation housing assembly 110. Thus,the interaction of the spring 116 pressing on the retention cap 120,which mates to the spherical head 124, and the tapered inner surface 130of the articulation housing assembly 110 serve to positionally retainthe driver tip 126 within the articulation housing assembly 110.

FIGS. 3A-3D illustrate the spherical head 124 and the driver tip 126 ingreater detail. As shown in FIG. 3A, the grooves 128 a, 128 b and 128 cform a generally ovular shape on the surface of the spherical head 124,and are wider near the diameter and taper moving toward thecircumference. The grooves 128 a, 128 b and 128 c are formed havinggenerally having a W-shape cross-section (see, FIG. 3D) within sphericalhead 124. In some implementations, the grooves 128 a, 128 b and 128 cmay be milled into spherical head portion at offsets of 120°. As shownin FIG. 3C, the grooves may extend over an approximately 120° arc acrossthe surface of the spherical head 124. Thus, it can be appreciated thatthe shape of the grooves 128 a, 128 b and 128 c maybe any shape suchthat the grooves cooperate with the pins 134 a, 134 b and 134 c provideapproximately 45-50° of angulation of the driver tip 126 with respect tothe input shaft 104 over a 360° rotation.

During assembly, the input shaft 104 is pressed in the articulationhousing assembly 110 and cross-pinned to the articulation housingassembly 110 using a pin 112. The pin 112 may be pressed-in and retainedby an interference fit with the shaft 104; the pin 112 may be welded inplace, or may be threaded into the shaft 104 or retained within afurther sleeve used to prevent pins 112, 134 a-134 c from backing out.Other attachment mechanisms may be used in place of the pin 112.

The various components above may be made from stainless steel, titanium,titanium alloy, ceramic, etc. The retention cap 120 may be fabricatedfrom PEEK, stainless steel, polyethylene, or any metallic or polymetricmaterial. The retention cap 120 may also include a TiN coating to limitwear and galling on the spherical head 124.

In some implementations, the various components of the driver 100 mayhave the following dimensions. The radius of curvature of the domedsurface 122 may be approximately 3.6 mm and may have a depth of 1.8 mm.The spherical head 124 portion may have a diameter approximately 6.5 mm.The recess 118 may have a depth of 1.5 mm to receive a portion of thespring 116. The retention cap 120 may have a total height of 3.0 mm. Thearticulation housing assembly may have a length of 15 mm and the taperedinner surface may begin 1.6 mm from the edge of the housing assembly.The inner diameter of the articulation housing assembly may be 7.1 mm.The cavity defined in the second end of the input shaft may have a depthof 3.5 mm.

During operation, as the user rotates the input shaft 104, torque istransmitted to the articulation housing assembly 110 via the press-fitand the pin 112. This torque is then transmitted from the articulationhousing assembly 110 to the driver tip via action of the pins 134 a, 134b and 134 c are received within the grooves 128 a, 128 b and 128 c ofthe spherical head 124 of the driver tip 126. The driver tip 126 thentransmits the torque to the attachment to turn, e.g., screws forinsertion into bone.

Thus, the ball-in-socket joint 102 of the present disclosure can bepositioned stabily in a multi-angle screwing/unscrewing operation. Inparticular, because the ball-in-socket joint 102 provides forapproximately 45-50° of angulation, the driver 100 maintains the drivertip 126 within a useful range of operation.

Referring now to FIGS. 5-8, the engagement of a screw with thearticulating driver 100 will be described. As shown in detail inexploded view of FIG. 5, a bushing 232 includes inner threads 506disposed at a distal end thereof and inner threads 508 disposed at theproximal end thereof. The diameter of the inner threads 506 and innerthreads 508 have a dimension that is complementary with an outerthreaded portion 514 of the screw 502 and a threaded region 510 of thedriver tip 126, respectively. The pitches of the inner threads 506 andouter threaded portion 514, and inner threads 508 and a threaded region510 may be respectively optimized to match. The outer threaded portion514 may be a conical thread or a straight thread. In someimplementations, the diameter of the inner threads 506 may be largerthan the inner threads 508 to allow the inner threads 506 to pass overthe threaded region 510, as will be described below. In someimplementations, the diameter of the inner threads 506 and the outerthreads 508 may be the same.

The bushing further includes a stop region 516, which cooperates with anaiming device or guide to halt forward progress of the bushing 232within the aiming device when the screw 502 is driven by thearticulating driver 100. Further details of the interaction of the stopregion 516 and the aiming device will be described below with referenceto FIGS. 9-12. Also as shown, the driver tip 126 includes at a distalend thereof a screw interface 512 that is adapted to engage acomplementary recess defined within the head the screw 502. The screwinterface 512 and complementary recess may be star-shaped, hexagonal,square, a polygonal shape, etc.

The operational engagement of the bushing 232, the driver tip 126 andthe screw 502 will now be described. FIG. 5 illustrates the componentsin a separated state, where initially, the bushing 232 is placed overthe screw interface 512 to engage the inner threads 508 with thethreaded region 510. The bushing 232 is rotated in, e.g., a clockwisedirection such that the inner threads 508 mesh with the threaded region510 to advance the bushing in the proximal direction. As shown in FIG.6, the bushing 232 may be moved in the proximal direction such that theinner threads 506 pass over the threaded region 510, as the diameter ofthe inner threads 506 may be larger than the threaded region 510. Inimplementations where the diameter of the inner threads 506 is equal toinner threads 508, the inner threads may engage the threaded region 510.As such, an intermediate state of engagement is achieved (shown in FIG.6) where the screw interface 512 and a portion of the threaded region510 protrude through the distal end of the bushing 232. Thus, the screwinterface 512 is positioned such that it can be received within acomplementary recess in the head of the screw 502.

Next, as shown in FIG. 7, the screw 502 is brought into proximity withthe screw interface 512 such that the interface may engage the head ofthe screw 502. An operator may then rotate the bushing 232 in e.g., thecounterclockwise direction to cause the inner threads 508 to mesh withthe threaded region 510, thus moving the bushing 232 in the distaldirection.

As shown in fully engaged view of FIG. 8, the bushing 232 is moveddistally until the inner threads 506 engage the threaded portion 514 ofthe screw 502. The engagement of the inner threads 506 and the threadedportion 514 serves to retain the screw 502 within the bushing 232. Thus,FIG. 8 illustrates the screw 502 when loaded into the articulatingdriver 100 and ready to be driven into an associated plate or portion ofbone.

With reference to FIGS. 9-12, the operation of the articulating driver100 to drive the screw 502 into an associated plate or portion of bonewill now be described. As shown in FIGS. 9-12, an aiming device or guide600 may be used to guide the screw 502. The aiming device 600 includes aplurality of aiming holes 604, each having a pin 602 that protrudesthrough an inner wall thereof at a distal end. An operator may drive thescrew 502 into, e.g., bone, by inserting the screw 502 into anappropriate one of the aiming holes 604. The screw 502 will pass throughthe aiming hole 604 and out of the aiming device 600. However, theaiming device 600 is sized such that the bushing 232 remains rotablypositioned within a proximal portion of the aiming hole 604 (see, e.g.,FIG. 10). As the operator drives the screw 502 using the driver 100, thescrew 502 and bushing 232 will rotate and move distally within theaiming hole 604 as the screw 502 engages the plate or bone.

As shown in FIG. 11, the distal movement will cause the stop region 516of the bushing 232 to engage the pin 602. As illustrated in FIGS. 5 and11, the stop region 516 may be formed having a jagged or zig-zag edge,such that the pin 602 is caught within a vertex 516 a formed by theedge. Engagement of the stop region 516 with the pin 602 will cause thebushing 232 to cease rotational and longitudinal movement (i.e., it willbe stopped within the aiming hole 604). It is noted that other designsmay be used to stop the advancement of the bushing 232 within the aiminghole 604 (e.g., frictional engagement).

After the bushing 232 is stopped, the application of torque to thedriver tip 126 will continue to rotate the screw 502 within the bushing232. Thus, the screw 502 will continue to be driven in the distaldirection along the longitudinal axis of the driver tip 126. As shown inFIG. 12, continuing to drive the screw 502 will rotate the threadedregion 514 within the inner threads 506, causing the threaded region 514to progress out of the distal end of the bushing 232. As such, the screw502 advances from the bushing 232 and will be released from the driver100. Operation of the articulating driver 100 may continue in order todrive the screw 502 into its final position through the continuedengagement of the screw interface 512 with the head of the screw 502.Once the screw 502 reaches its final position, the articulating driver100 may be withdrawn from the aiming device or guide 600.

Referring now to FIGS. 13-20, the engagement of a screw with thearticulating driver 100 will be described in accordance with anotherimplementation. Many of the details of the articulating driver 100 ofthis implementation are the same as the that described with reference toFIGS. 1-12; however, as shown in detail in FIGS. 13 and 14, a bushing732 includes inner threads 706 (FIG. 14) disposed at a distal endthereof and inner threads 708 disposed at the proximal end thereof. Thediameter of the inner threads 706 and inner threads 708 have a dimensionthat is complementary with an outer threaded portion 514 of the screw502 and a threaded region 510 of the driver tip 126, respectively. Thepitches of the inner threads 706 and outer threaded portion 514, andinner threads 708 and a threaded region 510 may be respectivelyoptimized to match. The outer threaded portion 514 may be a conicalthread or a straight thread. In some implementations, the diameter ofthe inner threads 706 may be larger than the inner threads 708 to allowthe inner threads 706 to pass over the threaded region 510, as will bedescribed below. In some implementations, the diameter of the innerthreads 706 and the outer threads 708 may be the same.

The bushing 732 further includes lobes 734, which cooperate with anaiming device or guide to halt forward progress of the bushing 732within the aiming device when the screw 502 is driven by thearticulating driver 100. The cooperation of the lobes 734 with theaiming device is described below in more detail with reference to FIGS.17-20. The lobes 734 may be formed such that they extend outwardly fromthe circumference of the bushing 732. Three or four lobes 734 may beprovided at the proximal end of the bushing 732; however any number oflobes may be provided.

The operational engagement of the bushing 732, the driver tip 126 andthe screw 502 will now be described. FIG. 14 illustrates the componentsin a separated state, where initially, the bushing 732 is placed overthe screw interface 512 to engage the inner threads 508 with thethreaded region 510. The bushing 732 is rotated in, e.g., a clockwisedirection such that the inner threads 508 mesh with the threaded region510 to advance the bushing in the proximal direction. As shown in FIG.15, the bushing 732 may be moved in the proximal direction such that theinner threads 506 pass over the threaded region 510, as the diameter ofthe inner threads 506 may be larger than the threaded region 510. Inimplementations where the diameter of the inner threads 506 is equal toinner threads 508, the inner threads may engage the threaded region 510.As such, an intermediate state of engagement is achieved (shown in FIG.15) where the screw interface 512 and a portion of the threaded region510 protrude through the distal end of the bushing 232. Thus, the screwinterface 512 is positioned such that it can be received within acomplementary recess in the head of the screw 502.

Next, as shown in fully engaged view of FIG. 16, the bushing 732 ismoved distally until the inner threads 506 engage the threaded portion514 of the screw 502. The engagement of the inner threads 506 and thethreaded portion 514 serves to retain the screw 502 within the bushing732. Thus, FIG. 16 illustrates the screw 502 when loaded into thearticulating driver 100 and ready to be driven into an associated plateor portion of bone.

With reference to FIGS. 17-20, the operation of the articulating driver100 to drive the screw 502 into an associated plate or portion of bonewill now be described. As shown in FIGS. 17-20, an aiming device orguide 800 may be used to guide the screw 502. The aiming device 800includes a plurality of aiming holes 804, each having circumferentiallobes 802 at a proximal end. The circumferential lobes 802 may extendinwardly from a center of each aiming hole 804 and receive the lobes 734of the bushing 732. An operator may drive the screw 502 into, e.g.,bone, by inserting the screw 502 into an appropriate one of the aimingholes 804. The screw 502 will pass through the aiming hole 804 and outof the aiming device 800. However, the aiming device 800 is sized suchthat the bushing 732 remains rotably positioned within a proximalportion of the aiming hole 804 (see, e.g., FIG. 18). As the operatordrives the screw 502 using the driver 100, the screw 502 and bushing 732will rotate and move distally within the aiming hole 804 as the screw502 engages the plate or bone.

As shown in FIG. 19, the distal movement will cause the lobes 734 of thebushing 732 to be received within the lobes 802. As illustrated in FIGS.13 and 17, the lobes 734 and the lobes 802 may be formed havingcomplementary shapes such that the lobes 734 are received with thecomplementary shaped lobes 802. Engagement of the lobes 734 and lobes802 will cause the bushing 732 to cease rotational and longitudinalmovement (i.e., it will be stopped within the aiming hole 804).

After the bushing 732 is stopped, the application of torque to thedriver tip 126 will continue to rotate the screw 502 within the bushing732. Thus, the screw 502 will continue to be driving in the distaldirection along the longitudinal axis of the driver 100. As shown inFIG. 20, continuing to drive the screw 502 will rotate the threadedregion 514 within the inner threads 506, causing the threaded region 514to progress out of the distal end of the bushing 732. As such, the screw502 advances from the bushing 732 and will be released from the driver100. Operation of the articulating driver 100 may continue in order todrive the screw 502 into its final position through the continuedengagement of the screw interface 512 with the head of the screw 502.Once the screw 502 reaches its final position, the articulating driver100 may be withdrawn from the aiming device or guide 800.

FIGS. 21-25 illustrate another embodiment of an articulating driver 1300of the present disclosure. As shown, the articulating driver 1300 mayinclude three components, a central screwdriver (FIG. 21), a centralsleeve (FIG. 22) and an outer, slip sleeve (FIG. 23). The centralscrewdriver 1301 may be a straight or jointed driver. As illustrated inFIGS. 24A and 24B, the central screwdriver may be a jointed driver whichis composed of a proximal shaft 1301 which has an interface 1301 a thatis adapted to provide a connection to, e.g., a handle for applyingtorque. The central screwdriver may include a jointed feature (e.g., auniversal joint 1308) and a distal portion containing the screwinterface 1306 a (e.g., a self retaining star-drive). Alternatively, thejoint mechanism 1308 may accomplished by beam coupling, spring coupling,jaw coupling, etc. Alternatively, the screw interface 1306 a may have ahexagonal, square, polygonal shape, etc. The central screwdriver mayinclude a distal tip 1306 that at a proximal end thereof, includes acircumferential groove 1313 to allow for retention of the centralsleeve.

Referring now to FIG. 22, the central sleeve may include a mechanism1302 to retain the central sleeve on the central screwdriver of FIG. 21.For example, the mechanism 1302 may be a spring-loaded quick couplingwith detents for retention on the circumferential groove of the centralscrewdriver. Between the proximal end and the distal tip, there is ahelical structure 1304 that may be provided to allow for bending of thejointed segment 1308 when the central sleeve is assembled. The nature ofthe helical structure 1034 allows it to act as a spring and hence bendwith the joint segment 1038. The helical structure 1304 may bemanufactured from a single solid tube with the central sleeve or may bebonded to the proximal and distal portion as a separate element. Thelater alternative would enable the use of any material that would beappropriate for the helical structure 1304. Such materials could be, butare not limited to, Nitinol, spring steel, certain grades of stainlesssteel or any other material which offers appropriate elasticity/memory.An additional benefit of the helical structure 1304 and its associatedmemory is that it prevents the loosening of jointed instruments, whichis often encountered when there is repeated use of jointed instrumentswith universal joints.

At the distal tip of the central sleeve, a distal portion 1305 isproviding having an outer diameter and length so as to have anappropriate interface with an aiming device or guide (e.g., 600) whichmay be used in association with the driver. An internal thread at thedistal tip 1309 (FIG. 25) may engage the screw which would have to haveeither a straight or conical thread on the external surface of its head.The pitch of this internal thread would be optimized to match that ofthe thread on the screw.

To assemble the screw to the driver, the screw interface 1306 a mayprotrude slightly out of the tip of the central sleeve. The screw wouldengage the screw interface 1306 a of the driver, which may be aself-retaining interface. Then, using the retention mechanism 1032 ofthe central sleeve to act also as a turning knob, the central sleeve isturned such that the internal thread 1309 engages the external thread ofthe screw head. In turning this central sleeve, one or both of thefollowing may occur, the screw is pulled further onto the screw driverinterface 1306 a or the helical structure 1304 elongates as the internalthread advances 1309 over the screw head. The screw is then rigidlyfixed to the screwdriver via the threaded connection to the centralsleeve and the connection of the central sleeve to the central driver.The screw is also connected to the central driver via the screwinterface 1306 a which allows for torque transmission and screwplacement.

As the operator advances the screw, there may be a tendency to hold thelength of the driver for guidance. If this holding occurs on the centralsleeve, it may result in early disengagement of the screw from thecentral sleeve as the central sleeve would remain stationary relative toa rotating screw driver and screw. In order to prevent this fromoccurring, an outer slip sleeve 1311 may be positioned on the outside ofthe central sleeve. This slip sleeve 1311 may freely rotate about thecentral sleeve due to a non rigid connection 1310. This connection 1310allows for rotation, but restricts translation. In addition, at thedistal end of the slip sleeve, there is located a flexible plasticsleeve 1312 that covers the helical portion from entangling surroundingtissue.

As the screw nears its final position, the thread on its head engages anassociated plate or portion of bone. However, in the insertion position,this head is covered by the central sleeve. Here, the user knows when todisengage the central sleeve. An alternative method involves theplacement of toothed features 1307 on the distal portion of the centralsleeve, which when approaching the final position, will engage into acounter-feature or the bone and will result in fixing the central sleevefrom rotating with the central driver. Further rotation of the centraldriver will result in automatic disengagement of the screw from thecentral sleeve. The helical structure will allow the central sleeve cancollapse with the advancement while the screwdriver-screw interfaceremains for optimum torque transmission. Once, the screw has beentightened into place, it will be no longer be connected to the driveritself and the driver is free to be removed.

In some implementations, in order to prevent deformation of the helicalstructure through over tightening of the central sleeve onto the screw,the helical structure may spiral in the opposite direction of the thread(i.e., counter-clockwise helical structure is provided for a clockwisethread). Therefore, over tightening will result in the helical structurecollapsing onto the inner screwdriver and hence preventing it fromdeforming outward.

FIG. 26 illustrates another embodiment that uses an external thread onthe central sleeve which would mate to a corresponding internal threadon the screw. Such a configuration may be used with variable anglescrews or pedicle screws, and screws with locking threads.

In yet another embodiment, the design of FIGS. 21-25 may omit thetoothed feature 1307. Turning of the screw with the head covered willresult in engagement of the central sleeve onto the aiming device.Subsequent turning of the screw after this condition is achieved willresult in lagging of the plate to the bone into which the screw ispurchased or vice-versa.

FIGS. 27-31 illustrate another embodiment of a joint 2702 of thearticulating driver of the present disclosure. As shown in FIGS.27A-27C, the articulating driver 2700 consists of an input shaft 2704that, at a first end 2706, connects to a handle (not shown) and has afirst spherical head 2708. The first spherical head 2708 is securedwithin an articulation housing assembly 2710 by a first pin 2712 thatpasses through a cavity 2709. The input shaft 2704 may be any type ofshaft capable of transmitting input torque from the handle or a powertool to which the input shaft 2704 is attached. A second spherical head2724 is formed at a proximal end of a driver tip 2726 and is secured tothe articulation housing assembly 2710 by a second pin 2734 that passesthrough a cavity 2729. When secured within the articulation housingassembly 2710, a ball 2718 formed at the distal end of the firstspherical head 2708 is received within a socket 2722 that is definedwithin a proximal end of the second spherical head 2724, the interactionof the various components is described further with reference to FIG.31.

As shown in FIG. 27C, enclosed within the articulation housing assembly2710 is the first spherical head 2708 of the input shaft 2704, a firstwasher 2712, a spring 2716, a second washer 2720, and spherical head2724 of the driver tip 2726. The spring 2716 is disposed between a firstwasher 2714 and a second washer 2720. The first washer 2714 has atapered edge that abuts the first spherical head 2708 and the secondwasher 2720 has a tapered edge that abuts the second spherical head2734. The spring 2716 exerts an expansion force on both the first washer2714 and the second washer 2720 to frictionally positionally retain thefirst spherical head 2708 and the second spherical head 2734 within thehousing assembly 2710 a user-set angulation. The proximal and distalopenings of the articulation housing assembly 2710 each have a chamferededge 2711 and 2730, respectively, that are adapted to abut a first base2705 and a second base 2727 to act as a stop to limit the totalangulation of the joint 2702, as described below.

FIGS. 28A-28C illustrate the first spherical head 2708 in greaterdetail. As shown in FIG. 28A, the cavity 2709 forms a generally ovularopening 2717 on a surface of the first spherical head 2708 (a bottomopening is not shown in the FIGS.). In some implementations, the cavity2709 may be milled into first spherical head 2708 having a generally“bow-tie” shape. As shown in the cross-sectional view of FIG. 28C, thecavity 2709 may be formed such the opening 2717 extends having anapproximately 22° arc in each direction with respect to a center axis ofthe cavity 2709 (providing a total arc of approximately 44° across thesurface of the first spherical head 2708). The “bow-tie” shaped of thecavity 2709 enables the first spherical head 2708 to be angulated withrespect to the first pin 2712 passing therethrough, which can beappreciated is positioned along the center axis of the cavity 2709 shownin FIG. 28C when the first spherical head 2708 is assembled into thejoint 2702.

FIGS. 29A-29C illustrate the second spherical head 2724 in greaterdetail. As shown in FIG. 29A, the cavity 2725 forms a generally ovularopening 2728 on the surface of the second spherical head 2724 (a bottomopening is not shown of the FIGS.). In some implementations, the cavity2725 may be milled into second spherical head 2724 having a “bow-tie”shape similar to the cavity 2709. As shown in the cross-sectional viewof FIG. 29C, the cavity 2725 may be formed such the opening 2728 extendsin a 22° arc in each direction with respect to a center axis of thecavity 2725. Thus, similar to the cavity 2709, the “bow-tie” shapedcavity 2725 enables the second spherical head 2724 to be angulated withrespect to the second pin 2734, which can be appreciated is positionedalong the center axis of the cavity 2725 shown in FIG. 29C when thesecond spherical head is assembled into the joint 2702.

As shown in FIG. 30A-30B, the articulation housing assembly 2710 definesholes 2736 into which the first pin 2712 and the second pin 2734 may bepressed. Openings 2740 are provided to enable easy cleaning of theinterior of the articulating housing assembly 2710. FIG. 30B illustratesthe chamfered edges 2711 and 2730 of the proximal and distal openings ofthe articulation housing assembly 2710. Each edge may be formed havingapproximately a 20° angle with respect to the longitudinal axis of thearticulation housing assembly 2710. The chamfered edges 2711 and 2730may abut the first base 2705 and the second base 2727 to limit the totalangulation at approximately 40°.

FIG. 31 illustrates a perspective view of the assembled joint 1702. Toassemble the joint 1702, the input shaft 2704 is inserted into thearticulation housing assembly 2710 and pinned to the articulationhousing assembly 2710 by the first pin 2712. The first washer 2712, thespring 2716 and the second washer 2720 are then placed within thearticulation housing assembly 2710. The driver tip 2726 is inserted intothe articulation housing assembly 2710 and pinned by the second pin2734. The pins 2712 and 2734 may be pressed-in and retained by aninterference fit with the articulating housing 2710; the pins 2712 and2734 may be welded in place, or may be threaded into articulatinghousing 2710. Other attachment mechanisms may be used in place of thepins 2712 and 2734.

The various components above may be made from stainless steel, titanium,titanium alloy, ceramic, etc. The first washer 2712 and the secondwasher 2720 may be made from PEEK. The spring 2716 may be any springhaving a spring constant to exert a sufficient force on the first washer2712 and the second washer 2720 to provide the aforementioned positionalretention of the first spherical head 2708 and the second spherical head2724 within the articulating housing 2710.

During use, a user can initially position the input shaft 2704 and thedriver tip 2726 by angulating the input shaft 2704 and the driver tip2726 to a desired total angulation. The approximately 22° of angulationof the first spherical head 2708 and the approximately 22° of angulationof the second spherical head 2724 may provide for a total angulation ofapproximately 44° of the driver tip 2726 with respect to the input shaft2704. However, as noted above, the total angulation may be limited toapproximately 40° by the interaction of the chamfered edges 2711 and2730 and the first base 2705 and the second base 2727. The angulationmay be maintained throughout a 360 rotation of the input shaft 2704 anddriver tip 2726 by the positional retention provided by the interactionof the spring 2716, the first washer 2714 and the second washer 2720 andthe constant velocity provided by the ball 2718 and the socket 2722.

As the user rotates the input shaft 2704, torque is transmitted to thearticulation housing assembly 2710 via the interaction of the first pin2712 within the cavity 2709 of the first spherical head 2708. Thistorque is then transmitted from the articulation housing assembly 2710to the driver tip via action of the second pin 2734 within the cavity2725 of the second spherical head 2724 of the driver tip 2726. Thedriver tip 2726 then transmits the torque to the attachment to turn,e.g., screws for insertion into bone.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed:
 1. A driver, comprising: an input shaft adapted to transmit torque, wherein said input shaft comprises an articulating joint at a distal portion and a circumferential groove at a proximal portion; a driver tip coupled to the articulating joint, the driver tip including an interface at an end thereof adapted to engage a screw, wherein the articulating joint allows articulation of the driver tip relative to the input shaft; and a sleeve extending over at least a portion of the input shaft and at least a portion of the driver tip, the sleeve including: a first threaded portion at a distal end thereof that is adapted to receive an exterior threaded portion of a screw head; a spring-loaded quick coupling with detents at a proximal end thereof; a helical structure between the proximal end and the distal end extending over the articulating joint which allows articulation of the articulating joint of the input shaft, wherein the input shaft and the driver tip are axially and rotatably movable within a central lumen of the sleeve; wherein rotation of the sleeve causes the first threaded portion to engage the exterior threaded portion of the screw head to further engage the driver tip within the screw head at the interface, and wherein rotation of the input shaft applies torque to the screw through the interface of the driver tip, and wherein retaining the detents of the spring loaded quick coupling in the circumferential groove fixes the axial position of the input shaft with respect to the sleeve such that the input shaft and the sleeve are axially retained, and further rotation of the input shaft relative to the sleeve elongates the helical structure.
 2. The driver of claim 1, further comprising: an aiming device and a stop region, wherein the stop region cooperates with the aiming device to hold the sleeve within the aiming device as torque is transmitted to the screw and the sleeve, such that engagement between the aiming device and the stop region prohibits rotation of the sleeve.
 3. The driver of claim 2, wherein after the sleeve is held within the aiming device and rotational movement of the sleeve is prohibited, continued torque applied to the screw via rotational movement of the input shaft and driver tip causes the threaded portion on the screw head disengage from the threaded portion of the sleeve, wherein the threaded portion of the sleeve and the threaded portion of the screw head have the same orientation.
 4. The driver of claim 2, wherein the stop region is formed as a toothed feature extending radially around an outer surface of the sleeve.
 5. The driver of claim 1, wherein the threaded portion included on the distal end of the sleeve includes inner threads disposed on an internal surface of the sleeve.
 6. The driver of claim 1, wherein the articulating joint is a universal joint.
 7. The driver of claim 1, wherein the interface of the driver tip includes at least one of a self-retaining star-drive, a hexagonal shape, a square shape, or a polygonal shape.
 8. The driver of claim 1, further including an elongated outer slip sleeve positioned around at least a portion of the sleeve.
 9. The driver of claim 8, wherein the outer slip sleeve includes a flexible portion proximate the coupling between the input shaft and the driver tip.
 10. The driver of claim 1, wherein the joint mechanism is axially aligned with the helical structure.
 11. The driver of claim 1, wherein the sleeve includes an elongated body portion provided adjacent the proximal end of the sleeve and a distal portion adjacent the distal end of the sleeve, the first threaded portion provided on the distal portion, wherein the helical structure is integrally formed in the elongated body portion.
 12. The driver of claim 11, wherein an outer diameter of the helical structure corresponds to an outer diameter of the elongated body portion.
 13. The driver of claim 11, wherein an outer diameter of the helical structure corresponds to an outer diameter of a proximal end of the distal portion.
 14. The driver of claim 1, wherein the helical structure comprises a band wound helically around a longitudinal axis of the sleeve, wherein a spacing between adjacent turns of the band defines a helical shaped opening extending between an outer surface of the sleeve and an inner surface of the sleeve. 